by David F. Kramer
Red blood cells, or erythrocytes, are the most abundant cells in the bloodstream and contain hemoglobin, which carries oxygen throughout the body. Dr. Jennifer Coates, veterinarian and author of the Dictionary of Veterinary Terms: Vet-speak Deciphered for the Non-Veterinarian, defines anemia as “a lower than normal number of red blood cells in circulation.”
Determining whether or not a pet is anemic is relatively easy. Coates says that an animal who is suffering from moderate to severe anemia will typically have “pale mucous membranes, rapid breathing, a fast heart rate, and may be lethargic and weak.” Simple blood tests that measure a pet’s red blood cell count can confirm the diagnosis.
According to Dr. Adam Denish, of Rhawnhurst Animal Hospital in Elkins Park, PA, “Anemia is categorized in many different ways, but there are two main distinctions: non regenerative and regenerative.”
“Regenerative anemia is when an animal’s bone marrow is trying to catch up with the anemia. For example, if an animal was losing blood through the GI tract from vomiting or diarrhea, the bone marrow should kick in and begin to create new cells,” says Dr. Denish
“If an animal has a nutritional deficiency (e.g., iron), certain types of cancer, or a chronic disease such as kidney failure that prevents the bone marrow from producing red blood cells in a normal manner, then that is considered a non-regenerative anemia,” says Coates.
While anemia has many causes, according to Dr. Denish, it presents itself in three basic forms.
Blood Loss: Dogs can lose blood any number of ways, including through disorders of the gastrointestinal tract. “Sometimes the blood is visible in the stool or when a pet vomits but at other times it is not,” says Coates. They can also lose blood from abdominal tumors and masses in the chest, urinary tract, or other locations in the body. Bleeding externally as the result of trauma is also a common cause of blood loss, but the bleeding would have to be severe or chronic to effect the red blood cell count.
Production Problems: As red blood cells die, they are normally replaced by the bone marrow. When the bone marrow is diseased or damaged or otherwise not working poorly, a dog’s system will be unable to keep up with this cycle of red blood cell regeneration.
Destruction: In these situations, something in the body is breaking down or killing red blood cells. Most of these cases are caused by certain types of immune disorders and/or infections.
The symptoms of anemia range from the behavioral to the physical. A dog that is lethargic, weak, or intolerant to exercise could possibly be suffering from anemia. Since red blood cells carry oxygen, a deficiency of them naturally causes less oxygen to be available for normal bodily functions, much less the increased demand of exercise.
If you feel your dog might be anemic, Dr. Denish suggests examining the eyes and gums of your dog. The conjunctiva, or the membranes in the upper and lower part of your dog’s eye, should be pink in color. If this membrane appears white or pale, this could be indicative of anemia.
Another common sign is pale gums. Your dog’s gums should also be a healthy, pink color. However, some breeds, such as Chows and Shar-Peis, have darkly pigmented gums, so it can be difficult to tell if these dogs are anemic by looking at their gums. When in doubt, get your dog to the vet for some bloodwork to be sure.
The most important part of treatment for anemia, says Dr. Denish, is to find the cause. If a loss of blood is caused by something like a ruptured spleen bleeding into the abdominal cavity, then the treatment would likely be to remove the spleen. Poisoning from rodenticides that cause bleeding can be treated with Vitamin K, which helps with the clotting mechanism. “The underlying problem is the most important issue when it comes to blood loss,” says Dr. Denish.
Dr. Coates adds that “identifying the cause of anemia is sometimes difficult. Diagnosing the immune disorders, cancers, and infections that may result in anemia can require advanced or specialized diagnostic tests.” She adds that once diagnosed, “bacterial infections that cause anemia often resolve with antibiotic therapy, and abnormal immune reactions can be treated with corticosteroids or other immunosuppressant medications.” Treatment for cancer-related anemia depends on the exact type of cancer involved.
“When we don’t yet know what the underlying cause is, there are two main courses of treatment. One is we give blood transfusions, or [two] we use certain medicines that help the blood count go up,” says Dr. Denish.
While you might not see dogs walking the streets with buttons saying “Pet me, I donated blood today,” the need for animal blood is very real in the veterinary world.
Doggie blood banking is big business. Pet Bloodmobiles will often visit dog and cat shows to maintain their resources, and there are local and national pet blood banks that provide real and synthetic blood to veterinarians for use in practices. “Smaller veterinary clinics don’t have the ability to store blood, so they often have a few canine and feline donors “on call” in case of emergencies,” says Coates.
Dogs do indeed have blood types but in some cases they can be transfused without performing a cross match or blood type—the first time at least. Subsequent transfusions will require cross matching or blood typing because while the first transfusion can slip by the body’s immune response, the body will eventually respond and launch a rejection with the next transfusion, if the blood types are not compatible.
The length of a course of treatment for anemia depends on the cause and severity of the condition. According to Dr. Denish, many cases of anemia are acute; that is, they come on suddenly and once the underlying problem is addressed, the anemia will resolve.
“The only cases that are usually treated long term occur with the destruction process or with production problems,” says Dr. Denish. “Some animals definitely have these issues and we treat them with medicines for three to six months. In cases of cancer or kidney failure, the animal doesn’t produce enough red blood cells. So there are diseases that have long term implications and animals might become chronically anemic.”
Treatments for severe or chronic anemia can be very costly. Transfusions are done in a hospital—a single treatment can cost several hundred dollars. Often, such treatments can involve an extended hospital stay or surgery with a cost that may run into the thousands.
If the anemia is acute, and caused by something like an ingestion of rat poison, then it often can be treated with medicine for a few hundred dollars. Costs will vary depending on the severity of anemia, where you live, and whether you had to take your dog to a late night emergency vet (amongst other potential factors).
Without treatment, cases of moderate to severe anemia can be fatal. Eventually, red blood cell counts can become so low that the remaining blood cells will not be able to carry enough oxygen to perform basic life functions.
A sudden bleeding issue can drop red blood cell counts to dangerous levels seemingly overnight, or a slow bleed can chip away at them for months with minimal physical effects. Either way, it is imperative that you get your dog to a vet if he or she exhibits any of the symptoms that could potentially be associated with anemia.